Memory circuit

Abstract

A memory circuit comprises a memory unit array and a peripheral circuit. The peripheral circuit consists of a charge pump circuit and a clamping circuit connected with the charge pump circuit, the clamping circuit comprises an overvoltage protection module and a clamping module which are connected in parallel, the overvoltage protection module is used for protecting an MOS (metal oxide semiconductor) transistor in a high-voltage circuit of a memory, the clamping module is used for clamping output voltage of the charge pump circuit, and an output end of the charge pump circuit is coupled to a first end of the clamping module. The memory circuit simultaneously guarantees reliability of threshold windows of memory units, reliability of the memory units and reliability of the transistor in the high-voltage circuit, and constant clamping voltage within a working temperature range can be realized.

Description

technical field [0001] The invention relates to the field of circuits, in particular to memory circuits. Background technique [0002] Non-volatile memory circuits such as EEPROM (Electrically Erasable Programmable Read-Only Memory) and FLASH need to generate an erasing voltage higher than 10V inside the chip, and use F-N tunneling effect or channel hot electron injection (CHEI) effect to EEPROM or FLASH memory performs erase and write operations, and the magnitude of the erase and write voltage will affect the threshold window of the memory cell, and will also affect the reliability of the memory cell and the reliability of the transistor in the high-voltage circuit used to control the operation in the memory. [0003] The EEPROM or FLASH memory circuit includes a memory cell array and peripheral circuits. The peripheral circuit includes a charge pump circuit. The charge pump circuit outputs an erasing voltage to perform erasing and writing operations on the EEPROM or FLASH...

AI Technical Summary

Problems solved by technology

The clamping circuit has good temperature characteristics and can achieve a constant clamping voltage within the operating temperature range. However, the clamping voltage is mainly determined by the bandgap reference source. The accuracy of the bandgap reference source is greatly affected by the process. To achieve higher accuracy, it needs Configure each chip when testing, which will increase the cost of testing, and the area of ​​the clamping circuit itself is also large

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